Separating and transporting piled metal sheets



Aug. 6, 1968 K. H. TAPPOLET ET AL 3,395,912

SEPARATING AND TRANSPORTING FILED METAL SHEETS 2 Sheets-Sheet 1 Filed May 2, 1566 I N V EN TORS KAPA HU/I P/C TAPQQLET AYLFPA'Q GlQSP/ICV/SQ M ram/[2 Aug. 6, 1968 K. TAPPOLET ET AL 3,395,912

SEPARATING AND TRANSPORTING FILED METAL SHEETS Filed May 2, 1966 2 Sheets-Sheet 2 INVENTORS XAPL HE VE/CH TAPPflL/ET ALFEED 652524045? United States Patent ,267 11 Claims. (Cl. 271-16) ABSTRACT OF THE DISCLOSURE A process and apparatus for separating and transporting metal sheets from a pile wherein the endmost sheet is separated from the pile by forces applied to opposite edges of the sheet for elastically bending the sheet, whereby the sheet is lifted and separated from the pile. The elastic bending forces are then released to permit the separated sheet to return to its original configuration. The sheet is then'subjected to a magnetic field having force lines substantially parallel to the plane of the sheet, which magnetic field maintains the separated sheets in a substantially parallel and spaced relationship. The sheets are then individually removed from the magnetic field by suitable conveyor means.

The invention concerns the gripping and separation of the sheets of a pile of metal sheets, as well as the transporting of the individual sheets to a place of work. A reliable gripping and especially separation of the sheets of a pile of metal sheets, as well as the transportation of the individual sheets to a place of work is very significant for all those sheet metal processing methods which use metal sheets from a pile, especially for those processes in which an unintentional adhering of several sheets to each other would lead to serious damage of the processing machines and to production losses.

It is the purpose of the process according to the invention to avoid such disadvantages, i.e., to guarantee a reliable gripping and separation of the sheets of a pile of metal sheets, as well as the transportation of the individual sheets to a place of work. Moreover, the process of gripping, separation and transporting of the sheets is time-saving and is eifected without large expenditures.

According to the invention, this is attained by the fact that a plurality of the lower or upper sheets of the pile are exposed to a bending force and are thereby elastically bent, whereupon they are released and exposed to the infiuence of a magnetic field having generally horizontal force lines, said magnetic field serving to keep the sheets at a distance from each other, whereupon the first sheet is seized and transported out of the magnetic field.

The bending force according to the invention, to which the lower or upper sheets of the pile are exposed, not only causes the removal of sheets off the pile of metal sheets, but, due to the shifting of the sheets with respect to each other, also eliminates any adhesion existing between adjacent sheets and the sticking-together of their cut edges. Sheets separated in such a way are kept at a distance from each other under the influence of a horizontal magnetic field, thus efiecting a reliable separation of the sheets which guarantees the engagement of the next sheet and its transportation out of the magnetic field.

For good operation, the first sheet in the horizontal middle plane of the magnetic field is engaged by mechanical means and is transported out of said magnetic field. This guarantees the possibility of transporting each sheet present in the magnetic field out of said magnetic field even when no more sheets are moved from the sheet metal 13,395,912 Patented Aug. 6, 1968 pile into the magnetic field. This is explained by the fact that each individual sheet endeavours to occupy the horizontal middle plane of the magnetic field and will, therefore, move into that position after the previous sheet has been engaged in the horizontal middle plane of the magnetic field and transported from this field. If the engagement of the respectively following sheet was done outside the middle plane, i.e., on that side of the magnetic field remote from the metal sheet pile, one or several sheets would be held stationary in the magnetic field so that no further sheets could be brought from the metal sheet pile into the magnetic field. A stable equilibrium condition of several sheets in the magnetic field always shows a symmetrical arrangement of the sheets with respect to the middle plane.

A further object of the invention is to provide an apparatus for carrying out this process, including a frame serving for the guiding and storage of the metal sheet pile, whereby the pile is supported by two opposite supporting elements or edges. One known device for the gripping and separation as well as transportation of the sheets of a metal sheet pile is provided with suction cups which seize the lowermost sheets of said metal sheet pile and move them downward over the supporting edges. By means of staircase-like slip-off structures located underneath, which gradually narrow the space for the passing through of the sheets adhering to the suction cups, any sheets which by chance are additionally picked up from the pile due to adhesion between adjacent sheets will be separated from the sheet that directly sticks to the suction cups. Eventually, this latter sheet rests against a device so that it can be further transported. During this process the suction cups are pulled oi the latter sheet in a downward direction. Thereupon, the suction cups rise again, and the whole procedure is repeated. Not to mention the inexpediency of the suction cups moving back and forth, this known device works slowly and unrellably.

It is the purpose of the apparatus according to the invention to avoid these disadvantages and to guarantee a fast, reliable and continuous gripping, separation and transporting of the individual sheets.

According to the invention, this is attained by a pair of shafts which form the supporting elements, the shafts of which partially extend into the region of the metal sheet pile and each has at least one longitudinal groove for receiving the sheet ends, whereby the two shafts are rotated in opposite directions and at the same phase relationship with regard to their longitudinal grooves, and by means of two magnets located below the pair of shafts and a transporting arrangement at least extending to the horizontal middle plane of the magnetic field. The arrangement of the magnets below the pair of shafts which support the sheet ends by means of the longitudinal grooves is advantageous because of the fact that, after the shafts have subjected the sheets to the bending force and thereafter released them, the sheets can drop into the magnetic field by utilizing the force of gravity.

Further details and advantages of the new process as well as of an embodiment of the apparatus according to the invention are explained more extensively by means of the attached drawings and the following description.

In the drawings:

FIGURE 1 is a schematic view illustrating the steps of the new process;

FIGURE 2 is a vertical central sectional view through an apparatus according to the invention;

FIGURE 3 is a sectional view along line III-III of FIGURE 2;

FIGURE 4 is a sectional view along line IVIV of FIGURE 2.

The schematic diagram of the process shown in FIG- URE 1 illustrates the preferable transportation route of 3 the sheets from the metal sheet pile into the magnetic field, that is to say, from above to below. However, the opposite route can also be used.

First of all, the lowermost sheets 1 of metal sheet pile 2 are, as shown by the two opposite arrows A, exposed to a bending force. As a result of this bending force and the stiffness of the sheets, sheets 1 are separated from the pile 2 and, due to their stiffness, are shifted with respect to each other, whereby the adhesion between them is eliminated, and also the cut edges of the sheets which may be hooked on each other are freed from each other. During the following discharge (arrows B) the sheets are released, as shown at 1a, and drop into a magnetic field existing between magnets 3, said magnetic field having essentially horizontal force lines, to keep the sheets at a distance b from each other. Thereupon, the first sheet 1c is seized and transported out of the magnetic field by the transporting elements 4. For the reasons already mentioned, during this process the first sheet in the middle plane of the magnetic field, from the side of metal sheet pile 2 close to the horizontal middle plane of the magnetic field, is seized and transported from the magnetic field. The respective next sheet consequently moves into the place of the first sheet. The indicated mechanical means 4 for the transportation of the sheets out of the magnetic field may, for example, be an endless conveyor belt formed in such a way that it moves the sheets in a direction perpendicular to the plane of the sheet of drawing. A second and preferred manner of transportation, however, consists in transporting the first sheet out of the magnetic field in a downward direction, that is to say, in the direction of arrow C.

It should be pointed out that the distance b of the sheets from each other in the magnetic field represents, among other things, a function of the number of sheets present in the magnetic field. The more sheets present in the magnetic field, the smaller is the existing distance b. It is evident that the number of sheets brought into the magnetic field has to correspond with the number of sheets transported out of the magnetic field to assure constancy of the distance b of the sheets from each other, once this distance has been chosen and providing the field intensity remains the same. The reasons for the fact that the magnetic field keeps the sheets present in this field at a distance from each other are known from the theory of magnetism.

The metal sheet pile shown in the drawing consists, for example of sheets, for instance tin-coated steel sheets, that are to be processed into can bodies, by first forming these sheets into bodies and then welding the sheet ends or joining them by folding and soldering.

FIGURE 2 illustrates an apparatus for carrying out the new process, which includes a frame 5 serving for guidance and storage of metal sheet pile 2. The pile is supported by two opposite support elements. According to the invention, these support elements are formed by a pair of shafts 6 which partially, advantageously up to half of their diameter, extend into the space below the metal sheet pile. Each shaft has at least one longitudinal groove 7, two longitudinal grooves being provided in each shaft in the illustrated embodiment, for engaging the sheet ends. The two shafts 6 are rotated in opposite directions E and F and at the same phase relationship as regards their longitudinal grooves 7, whereby the opposite edges of the sheet are simultaneously engaged by and moved at the same speed at the grooves 7. Two magnets 3 are arranged below the pair of shafts and there is also provided a transporting device 8, which at least extends between the magnets to the horizontal middle plane of the magnetic field.

As is evident from FIGURE 2, during higher pile pressures, several, for example two to three, sheets of the metal sheet pile resting on the pair of shafts 6 are engaged by the longitudinal grooves 7 of said shafts and are subjected to the bending force. Appropriately, a second corresponding pair of shafts 6a can be arranged be- 4 tween the first shaft pair 6 and the magnet 3. Accordingly, the sheets released by shaft pair 6 are first of all dropped only on the shaft pair 6a. Since only a few sheets are resting on these shafts 6a, and since, due to this fact, the pile pressure is not effective, this shaft air 6:: engages by its grooves 7a only the nearest sheet, which means that the sheets are moved separately into the magnetic field. The number of sheets present in the magnetic field can be controlled more easily, which is significant with regard to maintaining the distance b between the sheets.

The transporting device 8 of the embodiment shown in the drawing and preferably, consists of two vertical, synchronously driven worms 9 of the same pitch, which are arranged opposite to each other and at least extending to the horizontal middle plane of the magnetic field. These worms, which are located respectively between the legs 3a of magnets 3 which magnets have a U-shaped cross section (see FIGURE 3), engage with their worm flights 9a the nearest sheet 1c and transport it out of the magnetic field in a downward direction. Thereby it is evident that the worm flights 9 seizing the sheets have to have a pitch which is smaller than the distance b of the sheets from each other in the magnetic field in order to guarantee the seizure of only one sheet at a time. A preferable model of the worm has worm flights with a pitch 9b enlarging from the top toward the bottom. The enlargement of the distance between the sheets transported out of the magnetic field resulting from this is advantageous for the further transportation of the sheets to the place of work, for example by means of a second, endless conveyor device 10 which is arranged vertical to the axes of worms 9 at the end of the transporting route of the latter and which receives the sheets released by worms 9b. Advantageously, this second hauling device consists of a magnetic conveyor belt which holds the sheets reliably in their position on belt 10 during the further transportation (arrows D in FIGURE 3).

What is claimed is:

1. Process for gripping and separating the sheets of a metal sheet pile, as well as for transporting the individual sheets to a place of work, comprising the steps of subjecting at least one sheet at one end of the pile to a bending force and thereby elastically bending the sheet for separating same from the pile, releasing the bending force, then exposing the separated sheets to the influence of a magnetic field with essentially horizontal force lines so that said magnetic field keeps the sheets completely separated from each other, and then engaging one of said separated sheets and transporting it out of the magnetic field.

2. Process according to claim 1, in which the endmost sheet of the pile is subjected to a pair of oppositely directed forces applied to opposite edges thereof with said forces acting substantially in the plane of said sheet for elastically bending same whereby the sheet is lifted off the pile.

3. Process according to claim 2, in which releasing the bending forces permits the sheets to return to substantially their original configuration and wherein the then separated sheets are substantially parallel to and spaced from one another, said separated sheets then entering said magnetic field whereby the magnetic field maintains said sheets in said parallel and spaced relationship.

4. Process according to claim 1, in which the sheet is engaged while it is in the horizontal middle plane of the magnetic field and is transported out of said magnetic field.

5. An apparatus for gripping and separating the sheets of a metal sheet pile, as well as for transporting the individual sheets to a place of work, comprising:

a frame for guiding and storing the metal sheet pile, a pair of shafts forming support elements for supporting the pile, said shafts partially extending into the region of the metal sheet pile and each shaft having at least one longitudinal groove for engaging of the sheet ends, the two shafts being rotatable in opposite directions and at the same phase relationship with regard to their longitudinal grooves, two horizontally spaced magnets located on the other side of the pair of shafts from the pile for creating a horizontal magnetic field and a transporting device extending at least to the horizontal middle plane of the magnetic field.

6. An apparatus according to claim 5, in which a second, corresponding pair of shafts is located between the first pair of shafts and the magnets.

7. An apparatus according to claim 5, in which the transporting device comprises two vertical, synchronously driven worms with the same pitch, said worms being arranged opposite each other and at least extending to the horizontal middle plane of the magnetic field.

8. An apparatus according to claim 7, in which the worm flights have a pitch which enlarges from top to bottom of the worms.

9. An apparatus according to claim 7, in which a second, endless transporting device is arranged transversely to the axes of the worms and is located at the end of the transporting route of the latter.

10. An apparatus according to claim 9, in which the second transporting device is a magnetic conveyor belt.

11. An apparatus according to claim 5, in Which the magnets each have a U-shaped horizontal cross section and that the transporting device is arranged between the legs of these magnets.

References Cited UNITED STATES PATENTS EDWARD A. SROKA, Primary Examiner. 

